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.TH curl_url_set 3 "6 Aug 2018" "libcurl" "libcurl"
.SH NAME
curl_url_set - set a URL part
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLUcode curl_url_set(CURLU *url,
                       CURLUPart part,
                       const char *content,
                       unsigned int flags);
.fi
.SH DESCRIPTION
The \fIurl\fP handle to work on, passed in as the first argument, must be a
handle previously created by \fIcurl_url(3)\fP or \fIcurl_url_dup(3)\fP.

This function sets or updates individual URL components, or parts, held by the
URL object the handle identifies.

The \fIpart\fP argument should identify the particular URL part (see list
below) to set or change, with \fIcontent\fP pointing to a null-terminated
string with the new contents for that URL part. The contents should be in the
form and encoding they would use in a URL: URL encoded.

When setting part in the URL object that was previously already set, it
replaces the data that was previously stored for that part with the new
\fIcontent\fP.

The caller does not have to keep \fIcontent\fP around after a successful call
as this function copies the content.

Setting a part to a NULL pointer removes that part's contents from the
\fICURLU\fP handle.

By default, this API only accepts URLs using schemes for protocols that are
supported built-in. To make libcurl parse URLs generically even for schemes it
does not know about, the \fBCURLU_NON_SUPPORT_SCHEME\fP flags bit must be
set. Otherwise, this function returns \fICURLUE_UNSUPPORTED_SCHEME\fP for URL
schemes it does not recognize.

This function has an 8 MB maximum length limit for all provided input strings.
In the real world, excessively long fields in URLs cause problems even if this
API accepts them.

When setting or updating contents of individual URL parts, this API might
accept data that would not be otherwise possible to set in the string when it
gets populated as a result of a full URL parse. Beware. If done so, extracting
a full URL later on from such components might render an invalid URL.

The \fIflags\fP argument is a bitmask with independent features.
.SH PARTS
.IP CURLUPART_URL
Allows the full URL of the handle to be replaced. If the handle already is
populated with a URL, the new URL can be relative to the previous.

When successfully setting a new URL, relative or absolute, the handle contents
is replaced with the components of the newly set URL.

Pass a pointer to a null-terminated string to the \fIurl\fP parameter. The
string must point to a correctly formatted "RFC 3986+" URL or be a NULL
pointer.

Unless \fICURLU_NO_AUTHORITY\fP is set, a blank host name is not allowed in
the URL.
.IP CURLUPART_SCHEME
Scheme cannot be URL decoded on set. libcurl only accepts setting schemes up
to 40 bytes long.
.IP CURLUPART_USER
.IP CURLUPART_PASSWORD
.IP CURLUPART_OPTIONS
The options field is an optional field that might follow the password in the
userinfo part. It is only recognized/used when parsing URLs for the following
schemes: pop3, smtp and imap. This function however allows users to
independently set this field.
.IP CURLUPART_HOST
The host name. If it is International Domain Name (IDN) the string must then
be encoded as your locale says or UTF-8 (when WinIDN is used). If it is a
bracketed IPv6 numeric address it may contain a zone id (or you can use
\fICURLUPART_ZONEID\fP).

Unless \fICURLU_NO_AUTHORITY\fP is set, a blank host name is not allowed to set.
.IP CURLUPART_ZONEID
If the host name is a numeric IPv6 address, this field can also be set.
.IP CURLUPART_PORT
The port number cannot be URL encoded on set. The given port number is
provided as a string and the decimal number in it must be between 0 and
65535. Anything else returns an error.
.IP CURLUPART_PATH
If a path is set in the URL without a leading slash, a slash is prepended
automatically.
.IP CURLUPART_QUERY
The query part gets spaces converted to pluses when asked to URL encode on set
with the \fICURLU_URLENCODE\fP bit.

If used together with the \fICURLU_APPENDQUERY\fP bit, the provided part is
appended on the end of the existing query.

The question mark in the URL is not part of the actual query contents.
.IP CURLUPART_FRAGMENT
The hash sign in the URL is not part of the actual fragment contents.
.SH FLAGS
The flags argument is zero, one or more bits set in a bitmask.
.IP CURLU_APPENDQUERY
Can be used when setting the \fICURLUPART_QUERY\fP component. The provided new
part is then appended at the end of the existing query - and if the previous
part did not end with an ampersand (&), an ampersand gets inserted before the
new appended part.

When \fICURLU_APPENDQUERY\fP is used together with \fICURLU_URLENCODE\fP, the
first '=' symbol is not URL encoded.
.IP CURLU_NON_SUPPORT_SCHEME
If set, allows \fIcurl_url_set(3)\fP to set a non-supported scheme.
.IP CURLU_URLENCODE
When set, \fIcurl_url_set(3)\fP URL encodes the part on entry, except for
scheme, port and URL.

When setting the path component with URL encoding enabled, the slash character
is be skipped.

The query part gets space-to-plus conversion before the URL conversion.

This URL encoding is charset unaware and converts the input in a byte-by-byte
manner.
.IP CURLU_DEFAULT_SCHEME
If set, allows the URL to be set without a scheme and then sets that to the
default scheme: HTTPS. Overrides the \fICURLU_GUESS_SCHEME\fP option if both
are set.
.IP CURLU_GUESS_SCHEME
If set, allows the URL to be set without a scheme and it instead "guesses"
which scheme that was intended based on the host name. If the outermost
subdomain name matches DICT, FTP, IMAP, LDAP, POP3 or SMTP then that scheme
is used, otherwise it picks HTTP. Conflicts with the
\fICURLU_DEFAULT_SCHEME\fP option which takes precedence if both are set.
.IP CURLU_NO_AUTHORITY
If set, skips authority checks. The RFC allows individual schemes to omit the
host part (normally the only mandatory part of the authority), but libcurl
cannot know whether this is permitted for custom schemes. Specifying the flag
permits empty authority sections, similar to how file scheme is handled.
.IP CURLU_PATH_AS_IS
When set for \fBCURLUPART_URL\fP, this skips the normalization of the
path. That is the procedure where libcurl otherwise removes sequences of
dot-slash and dot-dot etc. The same option used for transfers is called
\fICURLOPT_PATH_AS_IS(3)\fP.
.IP CURLU_ALLOW_SPACE
If set, the URL parser allows space (ASCII 32) where possible. The URL syntax
does normally not allow spaces anywhere, but they should be encoded as %20
or '+'. When spaces are allowed, they are still not allowed in the scheme.
When space is used and allowed in a URL, it is stored as-is unless
\fICURLU_URLENCODE\fP is also set, which then makes libcurl URL encode the
space before stored. This affects how the URL is constructed when
\fIcurl_url_get(3)\fP is subsequently used to extract the full URL or
individual parts. (Added in 7.78.0)
.IP CURLU_DISALLOW_USER
If set, the URL parser does not accept embedded credentials for the
\fBCURLUPART_URL\fP, and instead returns \fBCURLUE_USER_NOT_ALLOWED\fP for
such URLs.
.SH EXAMPLE
.nf
int main(void)
{
  CURLUcode rc;
  CURLU *url = curl_url();
  rc = curl_url_set(url, CURLUPART_URL, "https://example.com", 0);
  if(!rc) {
    /* change it to an FTP URL */
    rc = curl_url_set(url, CURLUPART_SCHEME, "ftp", 0);
  }
  curl_url_cleanup(url);
}
.fi
.SH AVAILABILITY
Added in 7.62.0. CURLUPART_ZONEID was added in 7.65.0.
.SH RETURN VALUE
Returns a \fICURLUcode\fP error value, which is CURLUE_OK (0) if everything
went fine. See the \fIlibcurl-errors(3)\fP man page for the full list with
descriptions.

The input string passed to \fIcurl_url_set(3)\fP must be shorter than eight
million bytes. Otherwise this function returns \fBCURLUE_MALFORMED_INPUT\fP.

If this function returns an error, no URL part is set.
.SH "SEE ALSO"
.BR curl_url (3),
.BR curl_url_cleanup (3),
.BR curl_url_dup (3),
.BR curl_url_get (3),
.BR curl_url_strerror (3),
.BR CURLOPT_CURLU (3)
